On Wednesday, China conducted live-fire military drills in the Taiwan Strait, roughly 125 miles off the coast of Taiwan in the South China Sea. Although the drills were planned a month in advance, analysts believe they were intended as a signal of strength to Taiwan.

Taiwanese President Tsai Ing-Wen conducted her own naval exercise on April 14th, surveying Taiwan’s naval capabilities during a defense simulation. It came just a few days after China conducted its largest-ever naval display in the South China Sea. Chinese President Xi Jinping was pictured wearing naval garments and watching jets take off from Liaoning, China’s aircraft carrier.

China has repeatedly expressed zero tolerance for the furtherance of the Taiwanese independence movement, which President Ing-Wen avidly supports. But it is unclear whether military flexing on either side foreshadows conflict, or the two simply want to reinforce geographical claims to the highly contested South China Sea. China claims sovereignty to 90% of the sea, which carries over $3 trillion in trade each year and contains massive oil and gas reserves, as well as lucrative fisheries. They have also constructed numerous artificial islands and military facilities in the region.

On March 23rd, the United States carried out a “freedom of navigation” naval patrol just 12 miles from Mischief Reef, a Chinese artificial island in the South China Sea. The White House has previously stated that these naval and aircraft navigations are in its national interests.

The Trump Administration’s growing ties with Taiwan are raising Chinese suspicions regarding U.S. military and economic interests and intentions in the region. The U.S. State Department recently approved a license to allow American firms to sell Taiwan submarine production technology, potentially exacerbating the current tensions with China, who sees any official contact with Taiwan as a threat to its sovereignty. Chinese suspicions regarding Taiwan-U.S. relations initially spiked when President Tsai called President Trump to congratulate him for winning the election in 2016. This was the first time leaders of the two countries have directly spoken since 1979.

The future of the U.S.-Chinese relationship is unclear as the two have established themselves as global superpowers. Both strongly rely on each other for trade so it is critical for their partnership to be constructive, but with recent steps by the Trump Administration to grow ties with President Ing-Wen and as tensions rise in the South China Sea, a resolution may not come soon.